What is the significant bandwidth of an FM-phone transmission having a +/- 5-kHz deviation and a 3-kHz modulating frequency?

To calculate the significant bandwidth of a Frequency Modulation (FM) signal, amateur radio operators use a standard approximation known as Carson's Rule. The formula is: Bandwidth = 2 × (Peak Deviation + Maximum Modulating Frequency). In this scenario, the peak deviation is given as 5 kHz, and the highest modulating frequency is 3 kHz. First, you add the deviation and the modulating frequency together: 5 kHz + 3 kHz = 8 kHz. Next, you multiply that sum by 2 to account for both the upper and lower sidebands of the FM signal. Multiplying 8 kHz by 2 gives a total significant bandwidth of 16 kHz. This ensures approximately 98 percent of the transmitted power is contained within the calculated bandwidth.